Hey everyone! I recently got a bunch of DeWalt Flexvolt batteries for free in 6Ah, 9Ah, and 12Ah sizes, but unfortunately, they're all dead. Most of them show 18V but never hit 54V. I've been looking into how to repair them, but from what I've seen online, it seems really complicated. I have some basic electronics skills, like soldering and checking voltages, but I can't find any electrical schematics for these batteries. For the experts out there, do you think it's worth trying to repair them? How can I quickly tell if it's even a good idea to fix a battery?
2 Answers
Honestly, it might not be worth diving into unless you're looking to practice your electronics skills. But hey, maybe you could swap out the cells and make one or two good batteries from the three that are broken?
It really comes down to whether you're comfortable replacing the faulty cells. They’re sealed in plastic, so you’ll need to cut that away, and you’ll also need a tab spot welder to connect the new cells. I've seen some videos, and it looks like quite a bit of work!
Yeah, from what I've seen, it really does look like a lot of effort!

That’s a good idea! I could try fixing them as practice. Who knows, I might be able to build one battery from two or three!